sl66 tension cloth shutter

[raul]

well a have a problem on my negative i can see light penetrations on the edges

i am sure its not problem of the film back ,,
i think the cloth of the shutter is not total tensioned and it became a curve
and another question when the shutter is loaded there is more separation beetwin the back plate and the cloth

please have anyone this problem?
could be the cloth is too old or distensioned?

i have do a flash prove and i observe the light through the courtain
thank any idea i will thank you